Currently inferior memory is allocated by inferior mmap() but it is never
deallocated; despite the injected objfile incl. its symbols is freed. This was
intentional so that one can do for example:
inferior:
char *str = "foo";
GDB:
(gdb) compile code str = "bar";
I believe later patches will be needed to introduce full control over keeping
vs. discarding the injected module as being discussed in:
compile: objfiles lifetime UI
https://sourceware.org/ml/gdb/2015-04/msg00051.html
Message-ID: <20150429135735.GA16974@host1.jankratochvil.net>
https://sourceware.org/ml/gdb/2015-05/msg00007.html
As decided by Phil it is better not to leak inferior pages as users can
workaround the issue above for example by:
(gdb) compile code str = strdup ("bar");
I have checked that in fact gdb/doc/ (written by Phil) already expects the
injected code will be unmapped so that does not need to be changed:
compile code int ff = 5; p = &ff;
In this example, @code{p} would point to @code{ff} when the
@code{compile} command is executing the source code provided to it.
However, as variables in the (example) program persist with their
assigned values, the variable @code{p} would point to an invalid
location when the command exists.
gdb/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* arch-utils.c (default_infcall_munmap): New.
* arch-utils.h (default_infcall_munmap): New declaration.
* compile/compile-object-load.c (struct munmap_list, munmap_list_add)
(munmap_list_free, munmap_listp_free_cleanup): New.
(struct setup_sections_data): Add field munmap_list_headp.
(setup_sections): Call munmap_list_add.
(compile_object_load): New variable munmap_list_head, initialize
setup_sections_data.munmap_list_headp, return munmap_list_head.
* compile/compile-object-load.h (struct munmap_list): New declaration.
(struct compile_module): Add field munmap_list_head.
(munmap_list_free): New declaration.
* compile/compile-object-run.c (struct do_module_cleanup): Add field
munmap_list_head.
(do_module_cleanup): Call munmap_list_free.
(compile_object_run): Pass munmap_list_head to do_module_cleanup.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbarch.sh (infcall_munmap): New.
* linux-tdep.c (linux_infcall_munmap): New.
(linux_init_abi): Install it.
gdb/testsuite/ChangeLog
2015-04-28 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile.exp (keep jit in memory): Rename to ...
(do not keep jit in memory): ... this.
(expect 5): Change it to ...
(expect no 5): ... this.
It is planned the existing GDB command 'print' will be able to evaluate its
expressions using the compiler. There will be some option to choose between
the existing GDB evaluation and the compiler evaluation. But as an
intermediate step this patch provides the expression printing feature as a new
command.
I can imagine it could be also called 'maintenance compile print' as in the
future one should be able to use its functionality by the normal 'print'
command.
There was a discussion with Eli about the command name:
https://sourceware.org/ml/gdb-patches/2015-03/msg00880.html
As there were no other comments yet I haven't renamed it yet, before there is
some confirmation about settlement on the final name.
Support for the GDB '@' operator to create arrays has been submitted for GCC:
[gcc patch] libcc1: '@' GDB array operator
https://gcc.gnu.org/ml/gcc-patches/2015-03/msg01451.html
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
Phil Muldoon <pmuldoon@redhat.com>
* NEWS (Changes since GDB 7.9): Add compile print.
* compile/compile-c-support.c (add_code_header, add_code_footer)
(c_compute_program): Add COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE.
* compile/compile-internal.h (COMPILE_I_PRINT_OUT_ARG_TYPE)
(COMPILE_I_PRINT_OUT_ARG, COMPILE_I_EXPR_VAL, COMPILE_I_EXPR_PTR_TYPE):
New.
* compile/compile-object-load.c: Include block.h.
(get_out_value_type): New function.
(compile_object_load): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE. Set compile_module's OUT_VALUE_ADDR and
OUT_VALUE_TYPE.
* compile/compile-object-load.h (struct compile_module): Add fields
out_value_addr and out_value_type.
* compile/compile-object-run.c: Include valprint.h and compile.h.
(struct do_module_cleanup): Add fields out_value_addr and
out_value_type.
(do_module_cleanup): Handle COMPILE_I_PRINT_ADDRESS_SCOPE and
COMPILE_I_PRINT_VALUE_SCOPE.
(compile_object_run): Propagate out_value_addr and out_value_type.
Pass OUT_VALUE_ADDR.
* compile/compile.c: Include valprint.h.
(compile_print_value, compile_print_command): New functions.
(eval_compile_command): Handle failed COMPILE_I_PRINT_ADDRESS_SCOPE.
(_initialize_compile): Update compile code help text. Install
compile_print_command.
* compile/compile.h (compile_print_value): New prototype.
* defs.h (enum compile_i_scope_types): Add
COMPILE_I_PRINT_ADDRESS_SCOPE and COMPILE_I_PRINT_VALUE_SCOPE.
gdb/doc/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Compiling and Injecting Code): Add compile print.
gdb/testsuite/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.compile/compile-print.c: New file.
* gdb.compile/compile-print.exp: New file.
Currently the code fetches _gdb_expr address/types at multiple places, guessing
its parameters at multiple places etc.
Fetch it once, verify it has expected type and then rely on it.
While the patch tries to clean up the code it is still horrible due to the
missing C++ sub-classing.
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* compile/compile-object-load.c (get_regs_type): Add parameter func_sym.
Rely on its parameter count.
(compile_object_load): Replace lookup_minimal_symbol_text by
lookup_global_symbol_from_objfile. Verify FUNC_SYM. Set it in the
return value.
* compile/compile-object-load.h (struct compile_module): Replace
func_addr by func_sym.
* compile/compile-object-run.c: Include block.h.
(compile_object_run): Reset module variable after it is freed. Use
FUNC_SYM instead of FUNC_ADDR. Rely on it.
Provide a way to access current 'scope' during the do_module_cleanup stage and
associate more data with it.
gdb/ChangeLog
2015-05-16 Jan Kratochvil <jan.kratochvil@redhat.com>
* cli/cli-script.c (execute_control_command): Update
eval_compile_command caller.
* compile/compile-object-load.c (compile_object_load): Add parameters
scope and scope_data. Set them.
* compile/compile-object-load.h (struct compile_module): Add fields
scope and scope_data.
(compile_object_load): Add parameters scope and scope_data.
* compile/compile-object-run.c (struct do_module_cleanup): Add fields
scope and scope_data.
(compile_object_run): Propagate the fields scope and scope_data.
* compile/compile.c (compile_file_command, compile_code_command):
Update eval_compile_command callers.
(eval_compile_command): Add parameter scope_data. Pass it plus scope.
* compile/compile.h (eval_compile_command): Add parameter scope_data.
* defs.h (struct command_line): Add field scope_data.
This final patch adds the new "compile" command and subcommands, and
all the machinery needed to make it work.
A shared library supplied by gcc is used for all communications with
gcc. Types and most aspects of symbols are provided directly by gdb
to the compiler using this library.
gdb provides some information about the user's code using plain text.
Macros are emitted this way, and DWARF location expressions (and
bounds for VLA) are compiled to C code.
This hybrid approach was taken because, on the one hand, it is better
to provide global declarations and such on demand; but on the other
hand, for local variables, translating DWARF location expressions to C
was much simpler than exporting a full compiler API to gdb -- the same
result, only easier to implement, understand, and debug.
In the ordinary mode, the user's expression is wrapped in a dummy
function. After compilation, gdb inserts the resulting object code
into the inferior, then calls this function.
Access to local variables is provided by noting which registers are
used by location expressions, and passing a structure of register
values into the function. Writes to registers are supported by
copying out these values after the function returns.
This approach was taken so that we could eventually implement other
more interesting features based on this same infrastructure; for
example, we're planning to investigate inferior-side breakpoint
conditions.
gdb/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* NEWS: Update.
* symtab.h (struct symbol_computed_ops) <generate_c_location>: New
field.
* p-lang.c (pascal_language_defn): Update.
* opencl-lang.c (opencl_language_defn): Update.
* objc-lang.c (objc_language_defn): Update.
* m2-lang.c (m2_language_defn): Update.
* language.h (struct language_defn) <la_get_compile_instance,
la_compute_program>: New fields.
* language.c (unknown_language_defn, auto_language_defn)
(local_language_defn): Update.
* jv-lang.c (java_language_defn): Update.
* go-lang.c (go_language_defn): Update.
* f-lang.c (f_language_defn): Update.
* dwarf2loc.h (dwarf2_compile_property_to_c): Declare.
* dwarf2loc.c (dwarf2_compile_property_to_c)
(locexpr_generate_c_location, loclist_generate_c_location): New
functions.
(dwarf2_locexpr_funcs, dwarf2_loclist_funcs): Update.
* defs.h (enum compile_i_scope_types): New.
(enum command_control_type) <compile_control>: New constant.
(struct command_line) <control_u>: New field.
* d-lang.c (d_language_defn): Update.
* compile/compile.c: New file.
* compile/compile-c-support.c: New file.
* compile/compile-c-symbols.c: New file.
* compile/compile-c-types.c: New file.
* compile/compile.h: New file.
* compile/compile-internal.h: New file.
* compile/compile-loc2c.c: New file.
* compile/compile-object-load.c: New file.
* compile/compile-object-load.h: New file.
* compile/compile-object-run.c: New file.
* compile/compile-object-run.h: New file.
* cli/cli-script.c (multi_line_command_p, print_command_lines)
(execute_control_command, process_next_line)
(recurse_read_control_structure): Handle compile_control.
* c-lang.h (c_get_compile_context, c_compute_program): Declare.
* c-lang.c (c_language_defn, cplus_language_defn)
(asm_language_defn, minimal_language_defn): Update.
* ada-lang.c (ada_language_defn): Update.
* Makefile.in (SUBDIR_GCC_COMPILE_OBS, SUBDIR_GCC_COMPILE_SRCS):
New variables.
(SFILES): Add SUBDIR_GCC_COMPILE_SRCS.
(HFILES_NO_SRCDIR): Add compile.h.
(COMMON_OBS): Add SUBDIR_GCC_COMPILE_OBS.
(INIT_FILES): Add SUBDIR_GCC_COMPILE_SRCS.
(compile.o, compile-c-types.o, compile-c-symbols.o)
(compile-object-load.o, compile-object-run.o, compile-loc2c.o)
(compile-c-support.o): New targets.
gdb/doc/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Altering): Update.
(Compiling and Injecting Code): New node.
gdb/testsuite/ChangeLog
2014-12-12 Phil Muldoon <pmuldoon@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
Tom Tromey <tromey@redhat.com>
* configure.ac: Add gdb.compile/.
* configure: Regenerate.
* gdb.compile/Makefile.in: New file.
* gdb.compile/compile-ops.exp: New file.
* gdb.compile/compile-ops.c: New file.
* gdb.compile/compile-tls.c: New file.
* gdb.compile/compile-tls.exp: New file.
* gdb.compile/compile-constvar.S: New file.
* gdb.compile/compile-constvar.c: New file.
* gdb.compile/compile-mod.c: New file.
* gdb.compile/compile-nodebug.c: New file.
* gdb.compile/compile-setjmp-mod.c: New file.
* gdb.compile/compile-setjmp.c: New file.
* gdb.compile/compile-setjmp.exp: New file.
* gdb.compile/compile-shlib.c: New file.
* gdb.compile/compile.c: New file.
* gdb.compile/compile.exp: New file.
* lib/gdb.exp (skip_compile_feature_tests): New proc.
Jan Kratochvil
Joel Brobecker
Tom Tromey